Monday, October 15, 2007

It seems that some flight attendants are not very confortable on people using their iPhones during flights, even if on "flight mode". An iPhone user was detained for refusing to turn off his iPhone during a flight, because he was using it on "airplane mode", which restricts any communication features of the cellphone. He believed he wasn't breaking any rules because these special modes are created exactly to avoid that any harm is caused by the cellphone while it is being used on an airplane.

The problem lies on the fact that flight companies (and specially their employees, such as flight attendants) lack the knowledge that these special modes exist and do not cause any harm to the flight operation.

This reminds me of a little story that happened to me:

I travel quite a lot due to international conferences and project meetings and I never had any problems using devices on "flight mode" on airplanes.

Well, at least with flight attendants... The only problem I had, was actually a passenger that asked me if I had the time, and I showed her my cellphone (which was on "flight mode") and she started yelling (well, she was Italian, it was not yelling but you know how they can be quite volumous when talking :-) ): "You can't have your cellphone on. It's against the law".

I then spent 10 minutes telling her the difference between "flight mode" and normal mode and why the rules apply to the electric-magnetic fields and not the devices themselves, so it's okay to use the devices as long as the "communication features" are off. Soon enough she was asking me to check if her cellphone had that kind of functionality and if she could use on the flight :-)

I think the long talk with her didn't work, because every time the airplane reached some turbulence, she would give me that suspicious look to see if I was using the phone, kind of like she was saying: "it's your cellphone that's causing this turbulence!"

If it wasn't for my iPod and laptop I could have never survived the 25-hour flights to Hawai'i. Luckly, there's "flight mode" on devices :-)

1) The airlines say something like "Due to FAA regulations...". That is incorrect. Every Pilot should know that the use of electronic devices in airplanes are controlled by FCC regulations. It's on their written test. It really torques my off when they say that incorrectly, because if they get that wrong, then what else don't they do right?

2) All electronic consumer devices can wreck havok with cockpit instrumentation-- including those that have no transmission features at all. This is real. This isn't a problem while underway, because autopilot is fully GPS-ed, but it is definitely an issue during takeoff and landing, because pilots cannot use autopilot for takeoff and landing (that only works in sci-fi).

It is entirely appropriate for airline to apprehend any passenger that refuses to turn off an electronics device during takeoff or landing. The amount of interference that is acceptable by the FCC for consumer electronics is a much higher level than what effects cockpit instruments. Flight mode does-not and is-not meant to fix this.

One device might not be enough interference, but every phone, every radio, every iPod, and every computer in first-class might be. My ex-wife who was a pilot, actually read an NTSB crash report to me where the primary factor in the crash was due to people not turning off their electronic devices. Pilots know this, because they can see the affect when they turn on their own electronic devices.

3) Here is what flight mode does fix. When you are in an airplane your mobile phone will connect to multiple cell towers, in multiple places. This is due to the angle, basically you are almost just-as-close to many cell towers at the same time. This eats up bandwidth. By turning-off transmit-recieve capabilities on your phone you are preventing this.

Flight-mode accomplishes this and nothing more. This feature is a desire of the mobile carriers, not the airlines.

As far as interference is concerned, mobile phones don't interfere with GPS at-all. As such they are perfectly safe to use during flight, yes, it is even safe to make a call. They are not safe however during takeoff and landing, regardless of whether flight mode exists on your model, or is in use.

-- You convinced her, but you were not entirely correct. Unfortunately Flight Attendants don't have to take the Pilot's written test, and hence don't know why the rules are the way they are, which made her convince-able. Also, she probably never had a pilot show her what happens when you take an innapropriate electronics device in a cockpit. I do know people that have seen this first hand. Back in your seat? I assume that it is usually safe, but do you I want to be wrong in that assumption? No.

The FAA never made a regulation about electronics of any type, because that is the job of the FCC. They even point that out as part of pilot training. That said, you shouldn't be using your phone for any purpose during takeoff or landing. The pilot will let you know when he is no longer needing the non-GPS instruments: that's when they say that part about "You may now use approved communications devices." THAT is when you can turn on your iPhone in flight mode.

Yes, I was an Electromagnetic Compliance Engineer for many years. My job was to ensure and test that electronic devices that we developed without transmitting or being vunerable to electromagnetic interference to FCC and CE standard. The devices were safety-critical live saving devices. We even made the shielding products and the test chambers both in the EU and the USA. Many of our products were used in both military and civil aircraft.

Not all electronic equipment is a risk to aircraft systems. Aircraft systems are well-shielded. How else would we have a glass cockpit?

Transmitting devices on the whole I agree should be avoided, but some high voltage electronics like inverters for laptop screens can generate quite a signal!

GPS is a receiving technology, the GPS antennas are outside the aircraft. GPS interference would not affect the plane. More sensitive Nav systems may be affected, but not GPS.

BMI allowed BlackBerrys in flight mode but not iPhones. There needs to be more clarity, or a detector in the passenger cabin to tell flight attendants if there are transmitting devices?

The point is, most small electrical devices, including phones in flight mode are perfectly safe, as long as there are NO wireless functions in operation. The only time this may be a very slight risk is if the crew have these devices on their laps in the cockpit as distance plays a very important part of the equation. The effect is evident if you place your cellphone next to the speaker wires of your home PC and listen to the noise! But even when transmitting, the effect rapidly falls off with distance, and bear in mind aircraft have massively more sophisticated shielding.

Some modern aircraft shielding will even protect against EMP from a nuclear blast, so little Johnnie's Nintendo will have little effect.

We need to dispel the rumour and myth, educate cabin crews, and produce industry wide stadards to remove the grey areas.